Abstract B19: Aromatase inhibitor therapy, musculoskeletal symptoms and associations with vitamin D and C-reactive protein concentrations

Aromatase inhibitors are widely used for the treatment of post-menopausal breast cancer. Arthralgias and myalgias are major side effects. A case-control study was conducted to determine the prevalence and severity of musculoskeletal symptoms among women treated with aromatase inhibitors compared to women without a history of cancer and to examine the associations between symptoms and concentrations of C-reactive protein (CRP), a marker of systemic inflammation, and serum vitamin D for clues to their underlying etiology.

Cases were women undergoing adjuvant treatment for breast cancer with aromatase inhibitors (n = 102). Controls were women without a history of cancer (n = 146). Questionnaires assessed the presence, severity, and location of joint, muscle and bone pain. Participants with pain were asked to rate their pain on average, as well as the degree of pain at its worst, by marking a visual analogue scale. A blood sample was collected and processed within 4 hours of collection with serum stored at -70 degrees centigrade until assayed for vitamin D and CRP concentrations. Analyses were conducted using chi-square tests and unconditional logistic regression adjusting for age and season of blood draw.

The mean ages of cases and controls were 61.2 and 60.8 years, respectively. After adjustment for age and season of blood draw, cases were more likely than controls to complain of muscle pain (OR 1.75 95% CI 1.00-3.05) and bone pain (OR 1.77 95% CI 0.98-3.20) but not joint pain (OR 0.86; 95% CI 0.46, 1.61). Average pain scores for joint and muscle symptoms were similar between cases and controls but cases rated their average bone pain higher than controls (5.1 versus 3.4; p=0.009). Serum vitamin D and CRP concentrations were not statistically significantly different between cases and controls and were not associated with location or severity of pain.

Arthralgias and myalgias are common complaints among women, regardless of aromatase inhibitor therapy. Compared to controls, cases described their pain as muscle or bone pain rather than joint pain. These symptoms were not associated with serum vitamin D or CRP concentrations.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):B19.